From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751221AbaCHHvW (ORCPT ); Sat, 8 Mar 2014 02:51:22 -0500 Received: from mail-ee0-f42.google.com ([74.125.83.42]:54156 "EHLO mail-ee0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750832AbaCHHvV (ORCPT ); Sat, 8 Mar 2014 02:51:21 -0500 Message-ID: <1394265078.7215.11.camel@marge.simpson.net> Subject: Re: perf samples too long without perf running (?!?) From: Mike Galbraith To: Andy Lutomirski Cc: "linux-kernel@vger.kernel.org" Date: Sat, 08 Mar 2014 08:51:18 +0100 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-03-07 at 17:57 -0800, Andy Lutomirski wrote: > On recent (3.13) kernels, I'm frequently getting messages like: > > perf samples too long (2503 > 2500), lowering > kernel.perf_event_max_sample_rate to 50000 > > a few seconds to minutes after bootup. As far as I know, I'm not > using perf. What's going on here? 14c63f17b1 I get those all the time too, just building kernels. [ 598.583918] perf samples too long (2539 > 2500), lowering kernel.perf_event_max_sample_rate to 50000 Darn nmi_watchdog is an expensive employee. Scarier are the ones from 2ab00456ea when using perf. Firing the dog makes it all batter. -Mike